Glen Duncan is a writer from a Catholic, Anglo-Indian background whose previous novels have dealt with sexual guilt, dark mortifications of the flesh and reincarnations of the devil. That's the Catholic side of his upbringing taken care of: what's surprising is that he has drawn little attention to his Anglo-Indian heritage.

It's partly literary saturation which accounts for this: Duncan revealed that he originally conceived a mixed-race protagonist for his 2003 novel, Weathercock, "but took that element out because in the meantime there was Zadie Smith and Hari Kunzru and I didn't want to seem to be jumping on a bandwagon. I will write about it one day, when it's not so fashionable."

Duncan can be excused his disenchantment with literary fashion. His previous novel, Death of an Ordinary Man, featured a deceased narrator and was immediately trounced by Alice Sebold and Amy Tan pulling the same trick. But now he has finally resolved to take his chances with the long-delayed Anglo-Indian epic.

The narrator, Owen Monroe, shares the author's profile as a mixed-race writer in his late 30s, born in Bolton but living in London. Owen has published nothing as yet, apart from fulfilling a contract to produce two pornographic novels per year under the pseudonym Millicent Nash. For years he has planned to write the story of his parents' life, but doesn't know where to begin. "Start at the beginning," his father advises him, "go through the middle, then get to the end."

There's a telling scene in which Owen has lunch with a jaded publisher who says: "The market's in love with mixed race just now, but the market gets bored quickly. What you want is: Anglo-Indians - who are they? What are they like? But you do it through the burglar or the bent detective. There's a crime and mixed-race vein no one's tapped yet."

Fortunately, Owen chooses to ignore this and follows his father's advice to plot things simply as they occurred. The big breakthrough comes when he discovers a long-deleted paperback by one George Edward Nelson Skinner, a shady English businessman who implicated Owen's father in numerous swindles, and ultimately stymied his dream of a professional boxing career.

Owen concedes that this fortuitous discovery in a second-hand bookshop might leave a little too much to chance: "Moments more than half a century and half a planet apart connect. Someone with an insatiable appetite for a story, a plot junkie, is doing this." Yet Owen's obsession with destiny is primarily a means of manipulating stories in order to create an identity for himself.

The narrative is consistently coloured by the angst of belonging to an invisible race. Sometimes the tone can be bitter: "No one's on the Anglo-Indian's side ... you need a fucking ethnographic microscope to see us." But it can also be gently self-deprecating: "'And what colour is Owen?' my mum once asked my young niece. 'Beige' she said, eventually. 'Like Hovis'."

This sense of un-belonging accounts for Owen's strange habit of mooching around airports on his days off: "specifically the departures lounge, where you're nowhere and no one has any claim on you." Two things occur because of this peculiar behaviour - firstly he gets picked up by the police, who want to know why he keeps appearing on CCTV footage without seeming to go anywhere; and secondly he bumps into Scarlet, his childhood sweetheart, returning from New York where she has established herself (in a very Duncan-ish plot development) as a high-class Anglo-Indian call girl.

Having reconsummated their relationship, Owen and Scarlet trace their sense of exclusion back to incidents at school where they were dismissed or ignored "because we were beige". Scarlet then recounts witnessing the 9/11 attacks while dispassionately pulling a trick in a Manhattan penthouse, and feeling a complete sense of detachment as history was enacted in front of her. "We reject the political in favour of the personal, tragically or otherwise", Owen concludes. "That's what you're talking about on the roof, isn't it? Not caring because you're not part of it? I think all Anglo-Indians feel like that, actually."

The Bloodstone Papers is a sprawling, ambitious work, but it loops back and forth through history with remarkable lucidity and Duncan seems to have made a conscious effort to curb the ostentatious flourishes and baroque conceits of his earlier work. There are no twisted sadists, deceased narrators or reincarnated devils here: just the straightforward and ultimately very moving account of a man who discovers his voice by admitting that he was never sure how he was supposed to sound in the first place. Nor is there any evidence of mixed-race narrative falling out of favour just yet. For once, a Glen Duncan novel may have arrived at precisely the right time.